Metal fastening device.



UNITED STATES Patented March 8, 1904.

PATENT OEEICE.

METAL FASTENING DEVICE.

SPECIFICATION forming'part of Letters Patent No. 753,950, dated March 8,1904. Application filed November 14, 1903. Serial No. 181,201. (Nomodel.)

, Fastening Devices; and I do hereby declare that the following is afull, clear, and eXact description of the same, reference being had tothe annexed drawings, making a part of this specification, and to theletters of reference marked thereon.

The present invention has relation to that vclass of metal fasteningdevices comprising a rectangular or otherl form of metal plate having aplurality of vertical or transverse cor-V rugations therein and aregenerally used for strengthening or fastening together wood joints bydriving the fastening device .into the wood and for other purposes towhich a fastening of this character may be found useful.

Previous to my invention it was common to provide a series or pluralityof corrugations throughout the length of the fastenting device whichwere of uniform size, either fine or coarse corrugations, to adapt thefastening to dierent uses, such as coarse or fine work.

A fastening device with fine corrugations alone will not successfullyhold in soft wood on account of the insuficient hold of the corrugationsin the ibers of the wood, and a coarse corrugation alone cannot besuccessfully driven into the wood, in View of the width of the graincovered by the fastener, the fibers doubling over or the fasteningturning while being driven.

The objections to a fastening device having its corrugations uniform insize, as above set. forth, are entirely overcome by combining in one andthe same fastening device both a line and a coarse corrugation, therebysecuring the advantages without the necessity of aspecial form offastening device for each kind of work, and thus adapting the device foruse on fine or coarse work with success and without injury to the Wood.j

The invention consists of a metal fastening device constructedsubstantially as shown in the drawings and hereinafter described andclaimed. t

Figure l of the drawings is a perspective view showing a joint formed bymy improved fastening device; Fig. 2, a perspective view of thefastening device; Fig. 3, an edge view ofthe fastening device, showingan increased number of corrugations.

In the accompanying drawings, A B represent two pieces of wood, and C myimproved metal fastening device, forming the joint thereof, said devicebeing preferably formed with one of its edges sharp or reduced inthickness, as shown at a, to better facilitate driving the device intothe Wood. The corrugations of the fastening device increase in depth andwidth from the center thereof in a direction outward toward the ends-as,for instance, taking the central corrugation as the center, thecorrugation c upon each side thereof will increase in size, as will alsothe corrugations d over the preceding Vcorrugationsmand in Fig. 3 anadditional corrugation, c, is shown at each end, as I do not wish to beunderstood as limiting my invention to any specified number ofcorrugations or the size of the fastening device or the kind of metalfrom which it is manufactured, this being left entirely to themanufacturer. In the reduced size of the corrugationsV from the outerends of the fastening device to its center the stiffer and stronger thedevice will be at its center in proportion to the ineness of thecorrugations, these graduated corrugations enabling the device towithstand the twisting and bending strain when driven into the wood andafter it is in the wood, and the coarser the corrugations at the end ofthe device the greater will be the holding qualities thereof, and thecorrugations being of increased Width and depth, increasing in size fromits center outward, enables the device to be driven with much bettereffect, and the corrugations diverging instead of parallel will leave aWedge-shape center, as shown in Fig. Qof the drawings.

A fastening device constructed as herein described is equally applicableto fine or coarse work without the necessity of requiring aspecially-constructed fastening device for fine work and anotherfastening device especially adapted for coarse work.

The finer of the corrugations in my irnproved fastening device will comeat the intersection of the wood joint, and consequently greater will bethe resistance to withstand the strain of stretching or ofbending, suchas a fastening device would be subjected to at the meeting ends of thejoint, and the increased coarseness of the corrugations would increaseits holding power in the wood, and with these two features of theinvention embodied in a single fastening device a much iirrner jointwould be the result when used to fasten two pieces of wood together. asin boxes,crates, &c.

Having now fully described my invention, what I claim as new, and desireto secure by Letters Patent, isel. A metal fastening device having aplurality of graduated corrugations, substantially as and for thepurpose set forth. l

2. A metal fastening device having a plurality of corrugations whichincrease in size from its center in a direction toward its ends,ulstantially as and for the purpose speci- 3. A metal fastening devicehaving a plurality of corrugations increasing in depth and width in adirection from its center toward its ends, substantially as and for thepurpose described.

In testimony whereof I affix my signature in presence of two witnesses.

GEORGE CHAMBERS WYLAND.

Witnesses:

FRANK J. MILLER, B. S. RAKEsTRAw.

